Induction methods and apparatus



United States Patent O 3,259,308 INDUCTION METHODS AND APPARATUS De Witt C. Bennett, 4636 S. Meridian Ave., Wichita, Kans. Filed Sept. 1l, 1964, Ser. No. 395,798 12 Claims. (Cl. 2302tl6) This invention relates generally to improved `apparatus and methods for inducing the flow of a fluid into a pressurized chamber. More particularly, but not by way of limitation, this invention relates to an improved apparatus and method for inducing the flow of fluid from a nonpressurized reservoir into the cylinder of a reciprocating pump containing a pressurized fluid.

Various types of apparatus have been constructed in the past for introducing a fluid into a pressurized container. One type of apparatus for this purpose is commonly referred to as a lubricator and includes a pair of spaced valves located in a conduit which is connected with a pressurized chamber. .The section of conduit between the `spaced valves serves as a reservoir for the uid to be introduced into the pressurized chamber. The lubricator is operated by closing the valve located adjacent the pressurized chamber and opening the other valve, introducing the uid to be injected into the reservoir section of the conduit, closing the outer valve and opening the valve located adjacent the pressurized chamber, whereby the uid in the pressurized chamber mixes with the uid in the reservoir section. The lubricator device is adequate for introducing slugs of materials into pressurized chambers, but has the disadvantages of not providing a means of continuously inducing the iluids.

`Probably the most comonly used equipment for inducing a fluid into a owing stream of lluid under pressure involves the use of a venturi or orifice. The venturi or orifice is placed in the ow stream and a pressure drop created in the rapidly moving stream is used to induce iluid to flow from a reservoir into the stream. The obvious disadvantages of such a system are that the fluid in the stream must be owing at relatively high velocities and that the quantity of fluid injected may vary considerably as the velocity of the ilowing iluid changes.

In one sense, reciprocating pumps have for years provided a means of inducing a uid to ow from the fluid reservoir into the pump cylinder by reducing the pressure in the cylinder as the pump piston moves relatively away from the cylinder head. If the fluid reservoir from which the pump is drawing fluid is not pressurized, then it would be a simple matter to connect another circuit into the cylinder head and utilize the same reduction pressure to induce a second fluid to ow into the pump cylinder. However, when the pump is connected to a source of lluid, such -as a city water main, wherein the .pressure of the water source is .at 50 to 100 p.s.i., then the simple expedient of connecting the second conduit to the pump cylinder cannot be utilized. With the pressure of the water source at 50 to 100 pounds per square inch, the pump cylinder will contain the same pressure immediately upon opening the inlet valve to the pump. Therefore, it can be seen that a uid to be injected into the cylinder must either be raised above the pressure of the water source or some means provided in the pump for reducing the pressure therein Ibelow the pressure of the fluid which is to be injected.

Generally, this invention provides improved apparatus for and lan improved method of inducing iluid to ow from a substantially non-pressurized reservoir into a pressurized chamber that includes means for isolating a small portion of the chamber and reducing pressure therein to such an extent that the fluid to be induced will flow from the reservoir into the isolated portion of the cylinder or ice chamber and mixed with the pressurized fluid in the chamber.

One object of the invention is to provide an improved method and `apparatus for inducing fluid to flow from a substantially non-pressurized reservoir into a pressurized chamber.r

Another object of the invention is to provide an improved method and apparatus for inducing iluid to flow from a substantially non-pressurized lreservoir into the cylinder of a reciprocating pump, which cylinder contains a pressurized fluid.

Still another object of the invention is to provide an improved apparatus and method for inducing a iluid from a substantially non-pressurized reservoir into a pressurized chamber and simultaneously metering the quantity of iiuid thus induced.

A further object of the invention is to provide an improved reciprocating pump or use in car washing systems for inducing the flow of soap from a substantially nonpressurized reservoir into the pump cylinder containing water under pressure and simultaneously metering-the quantity of soap thus induced.

A still further object of the invention is to provide improved apparatus `which may be quickly and easily attached to an existing reciprocating pump whereby fluid may be induced into the cylinder of the pump from a substantially non-pressurized reservoir.

One other object of the invention is to provide improved apparatus for inducing uid from `a substantially nonpressurized reservoir into a pressurized cylinder which may be economically and easily manufactured.

One further object of the invention is to provide improved apparatus for inducing the flow of iluid from a substantially non-pressurized reservoir into a pressurized chamber which will require little or no maintenance.

The foregoing and additional objects and advantages of the invention will become more apparent as the following detailed description of the invention is read in conjunction with the accompanying drawing wherein like reference characters denote like parts in all views and wherein:

FIG. 1 is a View partly in cross-section and partly in elevation of an induction apparatus constructed in accordance with the invention and located in a reciprocating pump;

FIG. 2 is a segmental view of the apparatus of FIG. l, illustrating the apparatus in a different operational position;

FiG. 3 is a view similar to FIG. 2 and illustrating the apparatus in still another operational position; and,

FIG. 4 is a View similar to FIG. 2 but illustrating another embodiment of the invention in one stage of operation.

Referring to the drawing and to FIG. 1 in particular, shown therein and generally designated by the reference character 10 is the upper portion of a reciprocating pump. The portion of the pump 10 illustrated in FIG. l includes a cylinder member 12 and a head member 14 mounted on the cylinder member 12 by a plurality of threaded fasteners (not shown), and a portion of a piston 16 which is reciprocally mounted Within a cylinder bore: 18 in the cylinder member 12. The piston 16 is driven relatively toward andaway from the head member 14 by a conven- .tional driving means (not shown). As illustrated, a resilient sealing member 20 is disposed between the cylinder member 12 and head member 14 to prevent the escape of tluids therebetween.

In addition to the bore 18, the cylinder member 12 also includes an inlet passageway 22 and an outlet passageway 24 which are connected with the bore 18 by a recess 26 formed in the head member 14. The end of the inlet bore 22 adjacent the recess 26 is enlarged as shown at 28 to receive a conventional inlet valve 30.

The enlarged portion 28 of the inlet passageway 22 forms a downwardly facing shoulder 32 and an upwardly facing shoulder 34. The upwardly facing shoulder 34 forms a valve seat which is engaged by a valve disc 36. The downwardly facing shoulder 32 engages the upper end of a compression type spring 38. The opposite end of the spring 38 engages the valve disc 36 to urge the valve disc 36 into sealing engagement with the upwardly facing shoulder 34. The valve 30 is arranged to permit Huid flow through the inlet passageway 22 into the recess 26 and to prevent flow therethrough in the opposite direction.

The end of the outlet passageway 24 includes an enlarged portion 40 adjacent the recess 26 for receiving a conventional outlet valve 42. The enlarged portion 40 and the outlet passageway 24 form an upwardly facing shoulder 44 and downwardly facing shoulder 46. The outlet valve 42 is identical to the inlet valve 38 but is inverted relative to the position of the inlet valve 38. In this position, a valve disc 48 of the outlet valve 42 sealingly engages the downwardly facing shoulder 46. The lower end of a spring 50 is in engagement with the upwardly facing shoulder 44 and the upper end thereof is in engagement with the valve disc 48, thereby urging the valve disc 48 into sealing engagement with the downwardly facing shoulder 46; The arrangement of the outlet valve 42 is such that fluid can ow from the recess 26 into the outlet passageway 24 but flow therethrough in the opposite direction is prevented.

It should be pointed out that the inlet valve 36 and the outlet valve 4Z, which are illustrated in detail in FIG. 1, represent conventional inlet and outlet valves for a reciprocating pump and that other types of inlet and outlet valves may be substituted if desired.

Gne or more annular seals 52 encircle the piston 16 in sealing engagement with the bore 18 of the cylinder 12. The end of the piston 16 adjacent the head 14 is provided with a cylindrical protuberance 54 which may be hollowed out as illustrated or may be solid if desired.

As previously described, the head member 14 is provided with a recess 26 located in the lower surface thereof.

VVT he head member 14 also has a passageway 56 which entends vertically therethrough. The upper end of the passageway 56 has an enlarged counterbore 58 formed in a boss 60 located on the upper surface of the head member 14. The upper end of the counterbore 58 is provided with threads 62 which receive a threaded body 64 of a needle Valve 66,

A threaded nut 68 encircles the threaded body 64 and is provided to secure the needle valve 66 in the boss 66. A resilient sealing member 70, such as an O-ring, encircles the threaded body 64 and is disposed between the threaded nut 68 and the upper surface of the boss 60 to prevent fluid from passing by the threads 62. The needle valve 66 also includes a handle 72 which is attached to a valve stem 74.

The lower end of the valve stem 74 is provided with a frusto-conical portion 76 which serves to restrict the flow area through the passageway 56. It should be understood that the needle valve 66 is of conventional construction and can be replaced by any form of valve that can serve to restrict the flow area of the passageway 56.

The lower end of the passageway 56 entends through a cylindrical boss 78 which projects into the recess 26. That portion of the passageway 56 extending through the cylindrical boss 78 is enlarged forming a valve chamber 80 and providing an upwardly facing shoulder 82 therein. The passageway 56 below the upwardly facing shoulder 82 is sized to very closely receive the cylindrical protuberance 54 on the piston 16.

The valve chamber 80 also provides a downwardly facing shoulder 84 which is normally in engagement with a valve disc 86 disposed in the chamber 80. A compression type spring 88 has its lower end engaging the upwardly facing shoulder 82 and its upper end engaging the valve disc 86 to urge the disc 86 into sealing engagement with the downwardly facing shoulder 84.

An annular groove 90 encircles the cylindrical boss 78 near the juncture of the cylindrical boss '78 and the head member 14. A resilient and elastic sealing member 92 is disposed in the annular groove 90 encircling the cylindrical boss and is provided to prevent the flow of Huid from the recess 26 through a plurality of apertures or ports 94 in the boss 78 into the chamber 80, while permitting ow through the ports 94 in the opposite direction.

The boss 68 is also provided with a threaded opening 96 which extends laterally therethrough and is arranged to receive a conduit 98 which has its opposite end connected with a reservoir 108. lt can be appreciated from the foregoing structural description, that Huid contained in the reservoir 100 will gravitate through the conduit 98 and the opening 96 into the counterbore 58 and the passageway 56. Fluid from the reservoir 10i) is prevented from entering the chamber 80 due to the sealing engagement of the valve disc 86 with the downwardly facing shoulder 84.

Assume for the purpose of explaining the operation of the apparatus that the pump 10 is to be used to mix a concentrated liquid soap, which is contained in the reservoir 100, with water that is obtained from a city water supply. As previously mentioned, the city water supply will normally have a pressure between 50 p.s.i. and 100 p.s.i. superimposed thereon. With the city water supply connected tothe inlet passageway 22, the chamber formed by the recess 26 and the cylinder member 12 will have a pressure at least equal Ito the city water pressure therein.

As the piston 16 moves in the bore 18 toward the head member 14, the inlet valve 30 closes to prevent fluid flow from 4the recess 26 into the inlet passageway 22. Simultaneously, the outlet valve 42 opens to permit fluid contained in the recess 26 to flow through the outlet passageway 24. As the piston 16 nears the top of its stroke, the protuberance 54 will enter the lower end of the passageway 56 extending through the cylindrical boss 78 as shown in FIG. 1.

FIG. 2 illustrates the position of the piston 16 and protuberance 54 at the top of the piston stroke. As shown therein, -the protuberance 54 has fully entered the passageway 56 in the cylindrical boss 78. The fluids trapped within the chamber 80, due to the close lit between the protuberance 54 and the boss 78 and the closure of the valve disc 86, are discharged outwardly through the ports 94. The por-ts 94 are open to ow due to the high pressure in the chamber 80 deforming the resilient sealing member 92 outwardly, thereby uncovering the ports 94.

As the piston 16 begins its movement away from the head member 14, a relatively low pressure area will be created lin the chamber 80 by the retraction of the protuberance 54 therefrom. Simultaneously, the resilient sealing member 92 will close the ports 94 and the low pressure in the chamber 80 will cause the valve disc 86 to move away from the downwardly facing shoulder 84, depressing the spring 88 and opening the passageway 56 as shown in FIG. 3. Upon movement of the valve disc 86 away from the downwardly facing shoulder 84, the soap concentrate contained in the chamber 58 and the passageway 56 will move into the chamber 80. When the protuberance 54 has completely cleared the cylindrical boss 78, the soap concentrate contained in the chamber 8i) will be discharged into the bore 18 and recess 26 where it is mixed with water contained therein. Also, the spring 88 will bias the valve disc 86 into a sealing position with the downwardly facing shoulder 84, closing the passageway 56. FIG. 3 shows the valve disc 86 off the shoulder 84, ,the seal 92 closing the ports 94, and the protuberance 54 completely clear of the boss 78. Technically, such a simultaneous position of the parts may never occur, however, it is believed that FIG. 3 clearly demonstrates the sequence of operation.

Control of the quantity of soap concentrate admitted when the valve disc 86 moves away from the downwardly facing shoulder 84 is accomplished by adjusting the frustoconical portion 76 of the needle valve 66 to restrict the flow area -through the passageway 56. If desired, the needle valve 66 can be provided with graduations (not shown) to indicate the quantity or percentage of soap being induced into the pump 10. From the foregoing, it can be seen that for each stroke of the piston 16 a metered quantity of soap concentrate will be drawn into the pump from the reservoir 100.

The sequence that occurs during the induction of the soap concentrate from the reservoir 100 is as follows:

l) A small quantity of water is trapped in the chamber 80 between the upwardly traveling piston 16 and the valve disc 86.

(2) A small quantity of the trapped fluid is discharged from the chamber 80 through the ports 94.

(3) Movement of the piston 16 away from the head member 14, creates a relatively low pressure in the chamber 80.

(4) The low pressure in the chamber :80 permits the valve disc 86 to move relatively away from the downwardly facing shoulder 84, thereby, opening the passageway 56 for communication with the chamber 80.

(5) Soap concentrate from the reservoir 100 is drawn past the needle valve 66, through the passageway 56, and into the chamber 80.

(6) As the protuberance 54 clears the cylindrical boss 78, the soap concentrate in the chamber 80 is permitted to mix with water in the chamber formed by the recess 26.

Briefly summarizing the foregoing, the soap concentrate is induced into the pressurized pump chamber from `the reservoir 100 by isolating a small portion of the pump chamber, reducing the pressure in the isolated portion, and then placing the previously isolated portion in communication With the remainder of the chamber.

FIG. 4 illustrates another embodiment of ,the invention for inducing -luid into a pressurized chamber or cylinder. The embodiment of FIG. 4 is also illustrated in connection with the pump 10. The cylinder member 12 of FIG. 4 is identical in all respects to the cylinder member 12 as disclosed in connection with the embodiment of FIG. 1. It should be understood that the cylinder member 12 of FIG. 4 includes inlet valve 30 and outlet valve 42 as shown in FIG. l.

A head member 114 is securely mounted on the cylinder member 12 by a plurality of fasteners (not shown). The head member 114 is provided with a recess 116 which provides communication between the inlet and outlet valves 30 and 42, respectively and with the bore 18 in the cylinder member 12. The head member 114 is also provided with a boss 118 located on the upper surface thereof which is identical in all respects with the boss 60 of the head member 14. Like the boss 60, the boss 118 is adapted to receive a needle valve 66, as shown in FIG. 1.

A cylindrical boss 120 is formed on the lower surface of the head member 114 and extends into the recess 116. A passageway 122 extends through the head member 114 providing fluid communication from the reservoir 100 into a chamber 124 formed in the cylindrical boss 120.

The chamber 124 provides a downwardly facing shoulder 126 and an upwardly facing shoulder 128. The downwardly facing shoulder 126 serves as a seat for a valve disc 130 which is disposed in the chamber 124. The lower end of a compression type spring 132 is positioned on the upwardly facing shoulder 128 and the upper end of the spring 132 engages the valve disc 130 to urge the valve disc 130 into sealing engagement with the downwardly facing shoulder 126. An aperture 134 connects the chamber 124 with the recess 116. A comparison of the head members 14 and 114 shows the only significant difference between the two head members is that the head member 14 is also provided with the apertures 94 and resilient sealing ring 92.

The apparatus illustrated in FIG. 4 also includes a piston 136 which is positioned in the bore 18 for reciprocating movement. The piston 136 is provided on its upper end with a cylindrical protuberance 138 which has an outside diameter sized to closely fit within the aperture 134 of the cylindrical boss 120. A recess 140 is provided in the cylindrical protuberance 138 and a plurality of apertures 142 extend laterally through the protuberance 138. An annular groove 144 extends around the protuberance 138 and is sized to accommodate a resilient and elastic sealing member 146, which is illustrated as being an O-ring.

The arrangement of the sealing member 146 and the apertures 142 is such that fluid can flow from the recess into the recess 116, but fluid is prevented from flowing therethrough in the opposite direction. A comparison of the piston 136 of FIG. 4 with the piston 16 of FIG. 1 demonstrates that the only significant difference therebetween is that the piston 136 is provided with the apertures 142 and with the resilient sealing member 146.

The embodiments of FIGS. 1 and 4 operate in a substantially identical manner. However, :it will be realized that in the embodiment of FIG. 4, fluid will be discharged through the apertures 142 -in the piston 136 during the movement of the piston 136 toward the head member 114 instead `of through the apertures 94 located in the cylindrical boss 78 of the head member 14 as in the case of the embodiment of FIG .1.

The advantage gained in the embodiment of FIG. 4 lies primarily in the fabrication of the device. It can be readily appreciated that the protuberance 138 on the pist-on 136 can be drilled to provide the apertures 142 because of the easy access which may be had to the piston during the construction of the pump 10. However, because of the rather inaccessible location of the ports 94 in the head member 14, it can be seen that some difficulty is involved in forming the ports 94.

From the foregoing detailed description of the structure and operation of apparatus constructed in accordance with the invention it should be readily apparent that a relatively simple, yet highly efficient, method and apparatus have been described for introducing a fluid from a substantially non-pressurized reservoir into a cham-ber or cylinder containing a pressurized fluid. Furthermore, the fluid thusly induced can be accurately metered and controlled to obtain the precise mixture desired.

The foregoing embodiments, which have been described in detail, are presented by way of example only and it should be understood that many changes and modifications can be made thereto without departing from the spirit of the invention or the scope of the annexed claims.

What I claim is:

1. In apparatus for inducing a iluid into a cylinder having a reciprocating piston located therein and containing a fluid under pressure, the improvement comprising:

fluid `reservoir means;

means forming a flow passageway connecting said reservoir and cylinder;

pressure-responsive Valve means operably located in said flow passageway arranged to permit tlow from said reservoir to said cylinder and to prevent flow in the opposite direction;

means on the piston for intermittently isolating said passageway adjacent the cylinder and for intermittently lowering the pressure in the isolated portion of said passageway, whereby said valve means will open upon the lowering of the pressure in said passageway, thereby inducing fluid flow from said reservoir to the cylinder.

2. In apparatus for inducing :a fluid into a pump cylinder having a reciprocating piston located therein and containing a fluid under pressure, the improvement comprising:

a fluid reservoir;

means forming aflow passageway connecting said reser- 7. The .apparatus of claim wherein said means for voir and cylinder; relieving the pressure in said passageway includes:

one-way valve means operably located in said passagea recess in said prot-uiberance adjacent said passageway; way arranged to permit iiuid flow from said reservoir a plurality of ports extending laterally through said to the cylinder and to prevent iiow in the opposite 5 protuberance and connecting said recess .and said d-irection; bore; and,

said piston having a portion thereon sized to alternately a resilient member disposed over said ports arranged enter and leave said passageway as the piston reciproto permit luid ow from said recess into said bore Cates in the cylinder; and, and to prevent How in the opposite direction.

means for relieving the pressure in the portion of said 8. The apparatus of claim 5 and also including an passageway adjacent the cylinder when said piston adjustable valve ope-rably positioned in said passageway portion enters said passageway, whereby movement arranged to restrict-said passageway and thereby regulate of said piston portion relatively away from said onethe volume of iiuid iiowing through said passageway. way valve means causes a substantial reduction of 9. A method of inducing iluid flow from a reservoir pressure in said passageway to open said one-way l5 into a pressurized pump cylinder comprising the steps of:

valve and thereby inducing iiuid ow from said reservoir into the cylinder. 3. Apparatus for inducing a iiuid into a reciprocating pump f'nom a fluid reservoir, said apparatus comprising:

(l) placing fluid in said reservoir;

(2) isolating a portion of said cylinder adjacent the juncture of said reservoir with said cylinder;

(3) lowering the pressure in the isolated portion of a pum-p cylinder member having a bore there-in; said cylinder;

a head member mounted on said cylinder member and (4) intermittently placing the isolated portion of said having a passageway therein connecting said reserchamber in riuid communication with said reservoir; voir and bore; and, and, in communication with said cylinder.

a piston reciprocally mounted in said bore and Co- 16. A method of inducing fluid iiow from a reservoir operating with said head member to isolate a portion into a pressurized chamber comprising the steps of:

of said passageway adjacent said bo-re and to lower the pressure in the isolated portion of the passageway whereby iiuid is induced to ow from said reservoir into said bore.

isolating a portion of Athe chamber ,adjacent the juncture of the reservoir with the chamber; lower-ing the pressure in the isolated portion oi the chamber;

4;. Apparatus for inducting a fluid into a reciprocating 30 intermittently placing the -isolated portion of said pump from a iin-id reservoir, said apparatus comprising: .chamber in Huid communication with said reservoir;

a pump cylinder member having a bore therein; and, a head member mounted on said cylinder member and placing the previously isolated portion in communicah-aving a passageway therein connecting said resertion with the chamber. voir and bore; 11. Apparatus for inducing a iluid into a reciprocating a pressure-responsive valve located in said passageway adapted to permit fluid to fiow from said reservoir into said bore and to prevent flow into the opposite direction; and,

a piston reciprocally positioned in said bore and coa cylindrical protuberance located on one end thereoperating with said head and valve to intermittently of; isolate a portion of said passageway adjacent said a head member mounted on said cylinder member and bore and to intermittantly reduce the pressure in having a passageway connecting the reservoir and said isolated portion whereby fluid is induced to bore, said head member having a cylindrical boss iiow from said reservoir into said bore. depending therefrom and encincl-ing an enlarged por- 5. Apparatus ttor inducing a fluid into a reciprocating tion of said passageway sized rto receive said cylinpurnp containing iluid under pressure from a uid reserdrical protube'rance; voir, said apparatus comprising: a plurality of ports extending laterally through said a pump cylinder member having a bore therein; cylindrical boss connecting the enlarged portion of a piston recipnocally mounted in said bore and having said passageway with Said b-Ore;

a cylindrical protuberance located on one end therean annular resilient member encircling said cylindrical of; boss and disposed over said ports, said annular rea head member mounted on said cylinder member and silient member being arranged to permit fluid flow havin-g a passageway connecting 4the reservoir and from said passageway into said bore through said bore, said passageway having the portion thereof adports and to prevent ow `therethrough in the opjacent said bore sized to receive said cylindrical posite direction; and, protuberance; a one-way valve disposed in the enlarged portion of a one-way valve operably positioned in s-aid passagesaid passageway, said one-way valve including a Way arranged O Permit fluid OW TQIU Said reSCffvalve disk movable into and out of engagement with Vfllr lrlO Sald bore and t0 Prevent OW 111th@ OPPOSI@ 60 said head member within said cylindrical boss to dl'ectlorl andg prevent and to per-mit flow through said passageway, means for relieving the pressure in the portion of said and a Compression Spring having one end in engagg avtgis astswyorvlySgve ment with said cylindrical boss and the other end v l j a said pist-on relatively away from said head member lnengagemeI-ltkw1th s ald Vaima' dusk to yleldably has causes a substantial lowering of the pressure in said Said Va.ve dls toward sami head member thereby passageway, opening said one-way and inducing iluid prevemmg ow-thr9'ugh sald. passageway whereby flow from Said reservoir into said bore. movement of said piston relatively toward said head 6. The apparatus of claim 5l wherein said means for member @creases the pressu-re in the-en1arged Por'v relieving the pressure in said passageway includes: n o'n 0f Sad passageway t0 dlsplace sind annular Te' a plurality of ports extending from Said passageway silient member away from said ports to permit flow through said head member into said bore; and, Through Said POrS from Said enlarged P'OFOH into a resilient member disposed over said ports arranged Said bOr, and whereby movement of sai-d piston reto permit tlow from said passage-way into said bore latively @Way from Said head member lowers the and to prevent ilow in the opposite direction. pressure in said enlarged portion permitting said pump containing fluid under pressure from a tluid reservoir, said apparatus comprising:

a pump cylinder member hav-ing a bore therein; a pist-on reciprocally mounted in said bore and having annular resilient member to close said ports and moving said Valve disk'away from the head member to open said passageway inducing uid flow from said reservoir into said enlarged portion and, when said cylindrical protuberance is removed from said cylindrical boss, to permit the uid in the enlarged portion of said passageway to ow into said bore. 12. Apparatus for inducting a uid into reciprocating pump containing fluid under pressure from a fluid reservoir, said apparatus comprising:

a pump cylinder member having a bore therein;

a piston reciprocally mounted in said bore and having a cylindrical protuberance located on one end thereof, said cylindrical protuberance having a recess therein;

a head member mounted on said cylinder member and having a passageway connecting the reservoir and bore, said passageway including an enlarged portion adjacent said bore, said enlarged portion being sized to receive said cylindrical protuberance;

a .plurality of ports extending laterally throughsaid protuberance and connecting said recess and said bore;

an annular resilient member encircling said cylindrical protuberance and disposed over said ports to permit uid flow from said recess into said bore and to prevent Huid flow in the opposite direction therethrough; and,

a one-way valve operably positioned in the enlarged portion of said passageway, said one-way valve inl@ cluding a valve disk movable toward and away from said head member to prevent and to permit How through said passageway, respectively, and a colmpression spring disposed in said enlarged portion having one end in engagement with said head member and having the other end in engagement with said valve disk t-o yieldably bias said valve disk toward said head member to prevent flow through said passageway, whereby movement of said piston relatively toward said head member, with said protuberance disposed in the enlarged portion of said passageway, deforms said annular resilient member relatively outwardly to permit 'ow from said enlarged portion into said bore, and whereby movement of said piston relatively away from said head member permits said annular resilient member to close said ports and moves said valve disk relatively away from said head lmember to permit fluid to flow into the said enlarged portion, said fluid in the enlarged portion of said passageway being placed in communication with said bore when said cylindrical protuberance is moved out of said enlarged portion.

References Cited by the Examiner UNITED STATES PATENTS 30 ROBERT M. WALKER, Primary Examiner. 

1. IN APPARATUS FOR INDUCING A FLUID INTO CYLINDER HAVING A RECIPROCATING PISTON LOCATED THEREIN AND CONTAINING A FLUID UNDER PRESSURE, THE IMPROVEMENT COMPRISING: FLUID RESERVOIR MEANS; MEANS FORMING A FLOW PASSAGEWAY CONNECTING SAID RESERVOIR AND CYLINDER; PRESSURE-RESPONSIVE VALVE MEANS OPERABLE LOCATED IN SAID FLOW PASSAGEWAY ARRANGED TO PERMIT FLOW FROM SAID RESERVOIR TO SAID CYLINDER AND TO PREVENT FLOW IN THE OPPOSITE DIRECTION; MEANS ON THE PISTON FOR INTERMITTENTLY ISOLATING SAID PASSAGEWAY ADJACENT THE CYLINDER AND FOR INTERMITTENTLY LOWERING THE PRESSURE IN THE ISOLATED PORTION OF SAID PASSAGEWAY, WHEREBY SAID VALVE MEANS WILL OPEN UPON THE LOWERING OF THE PRESSURE IN SAID PASSAGEWAY, THEREBY INDUCING FLUID FLOW FROM SAID RESERVOIR TO THE CYLINDER. 